The Methods Core will provide infrastructure for advancing the science on cognitive/affective changes that accompany chronic illness and for ameliorating the symptoms associated with these changes using adaptive approaches and provider directed therapies (technical work). Cognitive/affective symptoms, so prevalent in chronic illness, are complex, multi-causal, non-linear and characterized by considerable variability. Thus, the methods for studying these symptoms must be able to characterize these aspects of the symptom experience for both groups and individuals. Trajectory science in nursing is expanding. Combined with longitudinal methods for both quantitative and qualitative data and innovative data visualization techniques, trajectory methods can be used to explore data in various ways to create different pictures of the phenomena and enhance insights that can be gained from studies of symptoms in chronic illness. The Methods Core will work closely with the Administrative Core and Scholarship/Mentoring Core to: Aim 1: Promote and expand bio-behavioral research and trajectory methods (longitudinal and longitudinal mixed methods designs, trajectory analyses, and visualization techniques) in studies to understand and ameliorate symptoms, symptom distress, and symptom sequelae for people with cognitive/affective changes in chronic illness. Aim 2: Provide consultation and support for trajectory methods. Aim 3: Support database development and management for Center Investigators. Aim 4: Collaborate with the Scholarship and Mentoring Core to promote learning and collaboration among center investigators through seminars and a journal club focused en measuring cognitive/affective symptoms and trajectory analyses.